Characterization of the maternal serum inflammatory profile during pregnancy according to socioeconomic status

In pregnancy, lower socioeconomic status (SES) is associated with adverse outcomes, which is partly attributed to chronic inflammation. Our study compared the maternal serum cytokine profiles in patients with low and high SES.

This retrospective cohort study compared maternal serum cytokine profiles between Medicaid-insured patients who delivered at an urban safety-net hospital (low SES) and privately-insured patients who delivered at a community-based academic hospital (high SES) in Atlanta, GA (n = 32-33/group). Serum samples were obtained during prenatal venipuncture from 13 to 38 weeks' gestation and the cohorts were matched by gestational age. Interferon (IFN)-γ, Interleukin (IL)-10, IL-1β, IL-4, IL-6, IL-8, and Tumor Necrosis Factor (TNF)-α were assayed from maternal serum samples using a standard ELISA assay.

Median concentrations of IL-6, a promotor of chronic inflammation, were higher in the low SES group (0.85 vs. 0.49 pg/mL, p < .001), while median levels of IL-1β, a potent monocyte activator, and TNF-α, a master regulator of acute inflammation, were lower in the low SES group (0.09 vs. 0.46 pg/mL, p < .001, and 1.23 vs. 1.58 pg/mL, p = .002, respectively) as compared to the high SES group. After adjusting for maternal age, obesity, hypertensive disorders, and gestational age at delivery, the differences in IL-6 and IL-1β by SES persisted (p = .0002 and p < .0001, respectively).

In this retrospective cohort study, there were significant differences in levels of pro-inflammatory cytokines during pregnancy for groups defined by SES, even after adjustment for confounding variables. Our data are foundational for further research to investigate SES-associated inflammation that may contribute to adverse pregnancy outcomes.